Emotient: artificially intelligent facial recognition

What it does: Uses artificial intelligence to scan a person's face and read their emotions

Price: Undisclosed

Acquired: January 2016

Founded: 2012

HQ: San Diego

Emotient can recognise a person's emotions at any given moment, in real-time, just by analysing their facial patterns. Marian Bartlett, a founder of Emotient and the company's lead scientist, explains how it works:

"It takes an image as input, and it scans that image for faces," she says. "And as soon as it finds those faces, it then does pattern recognition techniques in order to measure and detect the facial expressions in those faces."

One of Emotient's first wearable applications was a Google Glass add-on that the company hoped salespeople could use to judge whether a person really loves a product or not, according to TechCrunch.

One of the keys to Emotient's technology is being able to scan a person's face for emotions, but not store any personally identifiable information about them in the process. The use of face-scanning technology has been a privacy concern for many startups, although it's unclear what Apple intends to do with the company now that it can scan anonymously.

LearnSprout: education-tech startup

Vimeo / Mitchell Resnick

What it does: Builds software for teachers and school administrators to analyze data on students' performance

Price: Undisclosed

Acquired: January 2016

Founded: 2012

HQ: San Francisco

When Bloomberg first reported the acquisition, it said more than 2,500 school districts in 42 US states use LearnSprout’s software, according to its website.

The ed-tech company had raised $4.7 million in venture capital funding before it was acquired from firms such as Andreesen Horowitz, Formation 8, and Samsung Ventures, according to Crunchbase.

In recent years, Apple's traditional stronghold in the U.S. educational market has been eroded by low-cost laptops running Google's Chrome operating system.

In December, Apple CEO Tim Cook said that Google's Chromebook laptops are mere "test machines." According to data from Futuresource Consulting, a research firm that studies the educational market, over half of all devices sold to schools are now Chromebooks.

LegbaCore: A two-person security firm

LegbaCore founder Xeno Kovah now describes himself as the "Low Level Security Dude" at Apple on his LinkedIn page.LinkedIn

What it does: B est known for developing a proof-of-concept virus-worm hybrid called Thunderstrike 2 that targeted Mac computers.

Price: Undisclosed

Acquired: November 2015, but the acquisition was only properly discovered in February 2016

Founded: 2015

HQ: Washington D.C.

The worm that LegbaCore founder Xeno Kovah developed — a proof-of-concept virus-worm hybrid called Thunderstrike 2 that targeted Mac computers — was able to spread from MacBook to MacBook, even if the computers were not connected to the internet.

Kovah revealed on Twitter in November that he and his partner, Corey Kellenberg, had been hired by Apple to do "low level security." The move went unnoticed until another security researcher revealed it during a presentation at a security conference in December .

Kovah's worm virus was the first to attack Macs at the firmware level, according to Wired, which means it targeted the software that boots up before the computer's primary operating system, OS X. It's a valuable kind of attack because it usually can't be detected by antivirus and other security software.

Instead of exploiting their findings or selling it to the highest bidder, Kovah and team notified Apple of the vulnerabilities, which have since been fully patched. Although Apple does not pay "bug bounties" to researchers for finding security problems, the high road seems to have worked out for the founders of LegbaCore.

Carpool Karaoke: TV series spinoff with James Corden

Britney Spears and James Corden in an episode of "Carpool Karaoke."YouTube/The Late Late Show With James Corden

What it does: A viral segment on CBS's The Late Late Show featuring James Corden driving around with celebrities and singing

Price: Undisclosed

Acquired: July 2016

The "Carpool Karaoke" spinoff will be available on Apple Music worldwide and fans were not pleased when the news broke out.

The music giant has licensed 16 episodes at a half-hour each, current episodes are more like 10 or 15 minutes. Corden is not expected to be behind the wheel however, a different host will be cast at a later stage.

The episodes will stream weekly on Apple Music, which many of the show's followers may not be subscribed to.

Turi: machine learning platform for developers and data scientists

Turi.com

What it does: Provides tools and frameworks for other developers to incorporate machine learning and artificial intelligence into their apps.

Price: $200 million (£158 million)

Acquired: August 2016

Founded: 2013

HQ: Seattle

Turi was founded by a University of Washington professor and the company's website is still live, unlike all the other startups on this list.

This open source project was initially intended for applying large-scale machine learning to graph analysis, according to Crunchbase.

An example of its use is that it allows developers to build more advanced fraud detection into their applications.

Gliimpse: personal health data tracking

Apple

What it does: Gliimpse's product collates medical information into an easy-to-read profile for the patient

Price: Undisclosed

Acquired: August 2016

Founded: 2015

HQ: Silicon Valley

Gliimpse fits into Apple's larger ambitions to explore health technology. While the Apple Watch didn't bring about the new computing platform some were hoping for, Apple has learned people enjoy using it to track their health and fitness.

Here's how the company's website describes it before it was taken down:

"We've built a magical machine. It takes incomprehensible electronic medical records and turns them into understandable, standardized, coded elements (LOINC, RxNorm, CPT, ICD and SNOMED), and terminology that both humans and machines can easily understand and use. The Rosetta Stone meets machine learning."

Tuplejump: machine learning

Rohit Rai, co-founder of Tuplejump, now works at Apple.LinkedIn

What it does: A machine learning technology company

Price: Undisclosed

Acquired: September 2016

Founded: 2013

HQ: Hyderabad, India

Tuplejump is a machine learning technology company which aims to simplify data management technologies and make them extremely simple to use, according to a Wayback Machine capture of its about page. It has operations in both India and the United States.

The reason Apple had its eyes on Tuplejump was for its "FiloDB" project, according to a TechCrunch report which explains: "FiloDB was an open source project that Tuplejump was building to efficiently apply machine learning concepts and analytics to massive amounts of complex data right as it streamed in."

The lead engineer on FiloDB Evan Chan has been working at Apple since May 2016, as have two of the company's co-founders Rohit Rai and Satyaprakash Buddhavarapu, according to their LinkedIn profiles. Co-founder Deepak Alur, who was also Chairman at Tuplejump, now works at Anaplan as its head of engineering.

Indoor.io: indoor mapping platform

Co-founder of Indoor.io, Antti Saarinen.LinkedIn

What it does: Maps indoor spaces

Price: Undisclosed

Acquired: Unknown — 2015 according to its founder's LinkedIn profile, but only reported in December 2016

Founded: 2007

HQ: Finland

Apple reportedly made the hidden acquisition to improve its mapping service and ensure that it stays up to speed with Google.

The Bloomberg report of the acquisition states that Apple wants to use drones to capture and update map data, according to a Bloomberg source cited in the same report. Drones would potentially allow Apple to capture information quicker than its existing fleet of camera-equipped mini vans.